Throwing a grenade while Gunzerking causes you to throw 2 grenades.
The 2nd grenade does not cost ammo.
Keep It Piping Hot
While Gunzerking is in the process of cooling down you gain bonus Gun Damage, Melee Damage, and Grenade Damage.
The last round fired from your magazine gains massive Bonus Damage.
Guns with small magazine sizes receive a smaller bonus.
This skill works with all weapon types.